In telecommunication, the incoming information signal is corrupted with noise and jitter. The noise and jitter sources are many, a full description of which is beyond the realm of this application. However, what is important here is that noise and jitter degrades the quality of signal. It is very important the received signal is at a predetermined quality, measured in bit-error rate (BER), Q-Factor (Q), and signal to noise ratio (SNR); BER and SNR are two key parameters used to determine the channel performance.
The quality of signal impacts several transmission and network parameters, such as quality of service, link length, protection strategy, channel reassignment, bandwidth utilization, cost, etc.
In optical communications, because the fiber spans are long and the bit rates are high, channel performance increases in importance and links are more difficult to engineer.
In telecommunications, the current art relies on sophisticated error detecting and correcting codes, known as forward error correction (FEC), that have been added to each information frame. Thus, FEC adds overhead to and ups the line bit-rate of the information channel. Based on the FEC method, typically up to sixteen errors are detected and up to eight are corrected within a frame. From the detected error, the bit error rate (BER) is calculated and thus the channel performance.
However, this method requires several frames (or packets) to estimate the bit error rate and channel performance and thus a long time that compromises the overall system and network responsiveness to remedial action.